Abstract

This study investigated the interaction between hearing loss, reverberation, and age on the benefit of spatially separating multiple masking talkers from a target talker. Four listener groups were tested based on hearing status and age. On every trial listeners heard three different sentences spoken simultaneously by different female talkers. Listeners reported keywords from the target sentence, which was presented at a fixed and known location. Maskers were colocated with the target or presented from spatially separated and symmetrically placed loudspeakers, creating a situation with no simple “better-ear.” Reverberation was also varied. The target-to-masker ratio at threshold for identification of the fixed-level target was measured by adapting the level of the maskers. On average, listeners with hearing loss showed less spatial release from masking than normal-hearing listeners. Age was a significant factor although small differences in hearing sensitivity across age groups may have contributed to this effect. Spatial release was reduced in the more reverberant room condition but in most cases a significant advantage remained. These results provide evidence for a large benefit of spatial separation in a multitalker situation that is likely due to perceptual factors. However, this benefit is significantly reduced by both hearing loss and reverberation.

This work was supported by Grant Nos. DC004545, DC00100, and DC004663 from the National Institute on Deafness and Other Communication Disorders (NIDCD). N.M. was supported by a Ruth L. Kirschstein National Research Service Award for predoctoral fellows from NIDCD (F31 DC008440). This work partly fulfills the requirements for the Doctor of Philosophy degree at Boston University by N.M. We are grateful to Deborah Corliss and Janine Francis for their assistance in the Sound Field Laboratory. Thanks also to Virginia Best, Barbara Shinn-Cunningham, Melanie Matthies, Steven Colburn, Richard Freyman, and three anonymous reviewers for helpful comments on earlier versions of this manuscript.